Cut shortening into flour, celery seed and salt until particles are size of small peas. Sprinkle in water, 1 tablespoons at a time, tossing with fork until all flour is moistened and pastry almost cleans side of bowl (1 to 2 tsp. water can be added if necessary). Gather pastry into ball. Prepare celery seed pastry. Roll 2/3 of pastry into 13 inch square on lightly floured cloth, covered board. Ease pastry into 9 inch square pan; pour chicken filling into pastry lined pan. Roll remaining dough into 11 inch square; place over filling. Roll edges under; flute. Cut slits in center to allow steam to escape. Bake uncovered in 425 degree oven until crust is brown, 30 to 35 minutes.